a. Field of the Invention
This invention relates to the field of data processing systems. More particularly, this invention relates to the field of transaction driven data processing systems.
b. Related Art
Transaction driven data processing systems such as the CICS/ESA program produced by International Business Machines Corporation are long-lived, large, and complex systems (CICS/ESA is a trade mark of International Business Machines Corporation). CICS/ESA manages the passing of transaction commands between a large number of resource managers. These resources can be terminals, storage systems, printers, application programs etc. Each of these different resources may require different instructions to drive it, and require quite different management support by the CICS/ESA program to which it is attached. Having the support for these resources supplied by the CICS/ESA program helps improve the integrity and efficiency of the system.
One way of dealing with the addition of a new type of resource (e.g. a new class of terminals, or a new communications system), is to add code to the CICS/ESA program to support that new type of resource. The result of this is that resource support requires an ever increasing overhead to be carried by the CICS/ESA program. Alternatively, a new portion of programming interface can be added to the transaction managing computer program, but this has the result that the existing application programs running on the system may need to be re-written to drive this new programming interface. These problems are compounded by the fact that new type of resources are being produced at an ever increasing rate, and requiring a new release of the CICS/ESA program to support each new resource or group of resources to be made available.